If the number of integer callee-saves is odd, any FP callee-saves use 8-byte aligned...

If the number of integer callee-saves is odd, any FP callee-saves use 8-byte aligned LDP/STP.

If the number of integer callee-saves is odd, any FP callee-saves use 8-byte
aligned LDP/STP.  Since 16-byte alignment may be faster on some CPUs, align
the FP callee-saves to 16 bytes and use the alignment gap for the last FP
callee-save when possible.

    gcc/
        * config/aarch64/aarch64.c (aarch64_layout_frame):
        Align FP callee-saves.

From-SVN: r241419